Switch plate machine

ABSTRACT

This invention relates to a switch plate machine for rotating workpieces to work stations, e.g., machining stations. The Switch plate is mounted on bearings in the machine frame and is periodically turnable about equal angles. Workpiece receivers, for example chucks, are mounted on the said switch plate at equiangular intervals in axial thrust bearings parallel to the axis of the switch plate with play or tolerance in the radial direction. Centering members secured to the frame can be connected in rotation-resistant manner with any one of the workpiece receivers by an axial movement of the switch plate to center and align the workpiece receivers at each work station.

United States Patent J auch et al.

[4 1 Jan. 21, 1975 SWITCH PLATE MACHINE Assignee: said Jauch, by said Schafer Filed: Dec. 18, 1973 Appl. No.: 425,926

[56] References Cited UNITED STATES PATENTS 2/1973 Maier 74/826 5/1973 Crachy et al 74/813 L 3/1974 Maier 74/826 Primary Examiner-Samuel Scott Assistant Examiner-F. D. Shoemaker Attorney, Agent, or Firm-Webb, Burden, Robinson & Webb [57] ABSTRACT This invention relates to a switch plate machine for rotating workpieces to work stations, e.g., machining stations. The Switch plate is mounted on bearings in the machine frame and is periodically turnablc about equal angles. Workpiece receivers, for example chucks, are mounted on the said switch plate at equiangular intervals in axial thrust bearings parallel to the axis of the switch plate with play or tolerance in the radial direction. Centering members secured to the frame can be connected in rotation-resistant manner with any one of the workpiece receivers by an axial movement of the switch plate to center and align the workpiece receivers at each work station.

3 Claims, 3 Drawing Figures s sr-m/ s so /|s H/M/ 7\Y\ \W h t\\ 2 *LB S i 1; IS/ 20 2|/ /fll -e I Z PATENTEUJANZI 1975 I SHEET 1 or 2 SWITCH PLATE MACHINE On a well known switch plate machine of this kind (German Offenlegungsschrift No. 1,956,770) spindles are provided as centering members; they are mounted on hearings in the machine frame parallel to the axis of the switch plate and are axially movable with piston cylinder unit each. Each spindle has a truncated cone on its upper end which at the upper end position of the spindle engages a truncated-cone-shaped recess in the work piece receiver that is located above the spindle at the time. The switch plate is mounted on an axle in an axially immovable manner.

With these well known switch plate machines it is unavoidable that relative to the machine frame the spindles will have a certain amount of radial play which will increase in the course of time since a certain amount of wear is unavoidable due to the axial movement of the spindles which is repeated after every angular movement of the switch plate. In addition, the spindles cannot remain rigid against bending forces since in their upper end position they must extend far beyond their bearings in the machine frame, so that they can be engaged in the truncated-cone-shaped recess of the workpiece receivers. Tilting of the workpiece receivers which are connected with the spindles can, therefore, be avoided only if the switch plate is designed rigidly and is journaled with the least possible play.

One object of the invention consists in developing a switch plate machine of the described type in such a way that after every turn of the switch plate the machine will be able to arrange and hold the workpiece receivers in a particularly accurate and rigid manner. Thus, it should be possible for the workpieces, which are preferably clamped to the workpiece receivers, to occupy an exactly determined position with respect to the machining devices which are arranged on the machine frame or in its vicinity and which do not participate in the turning of the switch plate.

A further object of the invention consists in further developing a switch plate machine of the described type in such a manner that it will be possible to use a very light weight switch plate which will permit great accelerations and retardations during its rotational and axial movement.

These aims and further advantages can be obtained with a switch plate machine which will be more fully explained in the following with the aid of schematic drawings of an exemplary embodiment.

This invention relates to a switch plate machine for rotating workpieces to angularly spaced work stations. A rotatable switch plate is journaled in a frame and has workpiece receivers (chucks) positioned about the periphery thereof at equal angles. Hence, the switch plate may periodically rotate through equal angles to advance the workpieces to the next work station. Centering members are mounted on the frame below the switch plate at each work station. The chucks are mounted in the switch plate by thrust bearings which permit radial movement of the chuck relative to the switch plate; the chucks are angularly aligned and centered by engagement with the centering members resulting from relative movement between the switch plate and the centering members in the direction of the switch plate axis.

In the drawings:

FIG. I is a plan view of the switch plate machine;

Hg. 2 is a vertical axial section taken along line llll of FIG. 1;

FIG. 3 is an enlarged portion of FIG. 1.

On a machine frame 1 a housing 2 is rigidly secured. By means of a bearing 3 shaft 4 is rotatably and axially movably mounted. On the upper end of shaft 4 a switch plate 5 is mounted.

On the upper side of the housing 2 eight Hirth-type serrated centering members are arranged at equiangular distances from one another; in FIG. 2 two diametrically opposed centering members are shown and are designated by reference numerals 6 and 7.

On switch plate 5 eight workpiece receivers or chucks 8 to 15 are rotatably journaled with a certain amount of radial play and at equiangular distances from one another. On the lower face each of the workpiece receivers 8 to 15 is provided flat cone shaped serrations 16 (Hirth-type serrations). Serrations 16 fit exactly into Hirth-type serrations 17 on the upper face of the centering members 6 and 7 as well as of theother not illustrated six centering members which are rigidly arranged on housing 2. By means of serrations l6 and 17 which work together in pairs, the workpiece receivers 8 to 15 are absolutely fixed (centered and aligned) in their angular positions relative to the rotational axis of switch plate 5 when switch plate 5 occupies its lower end position as shown in FIGS. 1 and 3.

Shaft 4 of switch plate 5 is coupled by way of axial bearing 18 with a piston rod 19 on which a piston 21 is slidably fastened within a cylinder 20. Piston 21 can be selectively acted upon on its upper and lower face by pressure fluid which can be fed to cylinder 20 by way of channels 22 and 23.

In the drawings a situation is shown in which channel 22 and consequently also the chamber or cylinder 20 located above piston 21 are under pressure so that a considerable downwardly directed pulling force will be transmitted to the central portion of switch plate 5 by way of piston rod 19 and shaft 4 so that each of the workpiece receivers 8 to 15 with its serration 16 will be firmly pressed against serration 17 of a centering member (for example 6 or 7) disposed below serration 17.

Switch plate 5 designed to be elastically resilient in its radially outer zone so that all workpiece receivers 8 to 15 will be pressed with equal force against centering members 6 and 7 and so that thereby compensation can be made for manufacturing inaccuracies, as for instance in the elevation of the centering members. In order to increase the resilience of the radially outer zone of the switch plate 5 the example illustrated in the drawings shows radial slots 24 provided between workpiece receivers 8 to 15. These slots divide the radially outer zone of switch plate 5 into eight segments each of which is independently elastically resilient in the axial direction. The thickness of switch plate 5 in the axial direction as well as the length of slots 24 in the radial direction are preferably so dimensioned that the axial force transmitted from piston 21 to switch plate 5 will allow the switch plate to be deflected by no more than 1/10 mm.

In the vicinity of its outer periphery switch plate 5 has a circular cutout 29 for each of the workpiece receivers 8 to 15 and an axial thrust bearing 30 disposed around the cutout on the upper face of the switch plate. A chuck-like upper portion 31 of the associated workpiece receiver is supported onaxial thrust bearing 30. On upper member 31 a sleevelike central member 32 is fastened and is supported by a radial bearing 33 in the cutout 29 with the already mentioned radial tolerance. A lower member 34 is fastened to central member 32 by means of screws 35. Serration 16 is formed on the lower face of lower member 34 of each workpiece receiver.

For the clamping of a work piece that is not shown each workpiece receiver 8 to has two slides 36 which are slidably journaled opposite each other in a dimetral groove in the upper part of each workpiece receiver, For the purpose of moving the slides 36 each workpiece receiver has a tightening nut 37 which is supported by axial bearing 38 and 38 in central member 32 and in the lower part 34 of the workpiece receiver and is screwed onto a shaft 39. Shaft 39 is supported axially movably but non-rotatably in the central part 32 and on its upper end, as shown in FIG. 3, has wedge surfaces that are inclined toward the vertical axis of the chuck and cooperate with corresponding wedge surfaces of the slides. The lower side of the tightening nut 37 of each workpiece receiver is in the shape of a jaw coupling half, so that it can be engaged by a gripping (cooking lever) shaft (not shown) which is equipped with a corresponding coupling half. At that place on the switch plate machine where the workpieces are to be clamped to or released by the clamping devices, the gripping shaft may be pushed upwardly through an axial recess 40 in the centering member 7 in question and may be coupled to tightening nut 37 disposed thereabove.

Between each cutout 29 and each of the adjacent slots 24 of switch plate 5 a pressure member 41 is installed in a corresponding bore of the switch plate on the underside of the latter. The pressure members 41 are located on a common circle whose diameter is larger than that of the common circle on which the center points of cutouts 29 and consequently also the center points of the workpiece receivers 12 are located. Pressure members 41 press against the upper side of a flange 42 which is formed on the center portion 32 of each workpiece receiver 12. Since pressure members 41 do not lie in the drawing plane of FIGS. 1 and 3 and, therefore, would normally not be seen in these figures, for the purpose of clarification a pressure member of this type with the surrounding areas of switch plate 5 and flange 42 has been broken out and been projected into FIG. 3. It is the purpose of pressure members 41 to form precisely defined contact points between work piece receivers 12 and switch plate 5 so that the fabrication forces which occur during the machining of workpieces as well as the forces transmitted between the spur gears 16 and 17 will hold the workpiece receiver 12 in a certain position relative to switch plate 5.

In case it should be desired to turn the workpiece receivers 12 as a function of a turn of the switch plate about its own axis, on the underside of switch plate 5 a double pinion 43 is rotatably journaled on a vertical bolt 44 screwed to switch plate 5.

Each double pinion 43 has an upper spur gear which mates with a gear rim 45 secured to housing 2, as well as a lower spur gear which mates with a gear rim 46 formed on the lower part 34 of the associated workpiece receiver 12. Whenever switch plate 5 reaches its axially upper end position in which serrations l6 and 17 are out of engagement, and when switch plate 5 in this position is turned by the angular distance between two adjacent workpiece receivers 12, (by 45 in the illustrated example) then all the workpiece receivers 12 will rotate depending on the number of gear teeth of the two spur gears of double pinion 43 by 45 or 60 or or for example.

As shown in FIG. 2, for turning switch plate 5 a sinusoidal ascending curve 48 is provided at the periphery of a control shaft 47; this curve has a non-ascending feed-in and a nonascending run-out and cooperates with a disc 50 provided on shaft 4, the said disc having follower pins which consecutively mesh with curve 48.

For the described switch plate machine machining devices are provided which may be of well known design and are not part of this invention and, therefore. need not be shown. The machining devices are fastened on machine frame 1 in such a way that, for instance. in every angular position of switch plate 5 in which serrations 16 and 17 are in engagement, each of the workpieces in the workpiece receivers 8, 9, 10 and 11 as well as 13, 14 and 15 can be worked on by one or more of the machining devices, while at the same time a machined workpiece can be removed from workpiece receiver l2 and can be replaced by an unprocessed workpiece.

As soon as all the machining devices have finished their task, the space above piston 21 in cylinder 20 is relieved of pressure means, while pressure means are introduced through channel 23 into the chamber below piston 21, so that piston 21 with piston rod 19, shaft 4 and the switch plate 5 will be moved upwardly with all the workpiece receivers. As soon as serrations 16 and 17 are out of engagement, control shaft 47 is turned by one revolution so that shaft 4 with switch plate 5 will be turned by 45. Thereupon the switch plate with all the workpiece receivers will again be lowered by introducing pressure means into the cylinder chamber above piston 21 and relieving the pressure in the cylinder chamber below the piston, so that the serration 16 of each workpiece receiver will be in engagement with one of the serrations 17 on housing 2. Since in this way all the workpiece receivers are rigidly connected with housing 2 and with machine frame 1, another work cycle of the machining devices can begin.

1. A switch plate machine for rotating workpieces to angularly spaced positions comprising,

a machine frame,

a switch plate which is journaled in the machine frame such that it can be periodically rotated by equal angular distances and can be reciprocated in the direction of its axis of rotation,

means for rotating the switch plate,

means for the axial reciprocating movement of the switch plate,

a plurality of thrust bearings which are arranged on the switch plate about its axis of rotation at equal angular intervals,

a plurality of workpiece receivers each of which is journaled in one of the thrust bearings parallel to the axis of rotation of the switch plate with radial tolerance and Hirth-type serration on its lower face,

and a plurality of centering members which are rigidly affixed to the machine frame around the turning axis of the switch plate at equal angular intervals and have Hirth-type serration on their top face which mate axially with the serration of the workpiece receivers after every turn of the switch plate 6 and which can be brought into and out of engage- 3. A switch plate machine according to claim 2 ment by an axial movement of the switch plate. wherein the radially outer zone of the switch plate is di- 2. A switch plate machine according to claim 1 vided by radial slots into elastic segments each ofwhich wherein the switch plate is elastically resilient in the carries one workpiece receiver. axial direction near the periphery thereof. 5

UNITED STATES PATENT OFFICE CERTIFICATE OF COBREQTION Patent 3. 861. 245 Dated Januarv 21, 1975 I Kurt Jauch and Rolf Schafer It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3 Line 10 --dimetralshould read --diamet'ral--.

Column 3 Line 23 --cooking-=- should read --=cocking--=.

Signed and sealed this 17th day of June 1975.

(SEAL) Attest:

S, Z 'EARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks ORM PO-105O (10-69) USCOMM'DC 60376-P59 U,S, GOVERNMENT PRINT NG OFFICE: I969 O-3$$-334 

1. A switch plate machine for rotating workpieces to angularly spaced positions comprising, a machine frame, a switch plate which is journaled in the machine frame such that it can be periodically rotated by equal angular distances and can be reciprocated in the direction of its axis of rotation, means for rotating the switch plate, means for the axial reciprocating movement of the switch plate, a plurality of thrust bearings which are arranged on the switch plate about its axis of rotation at equal angular intervals, a plurality of workpiece receivers each of which is journaled in one of the thrust bearings parallel to the axis of rotation of the switch plate with radial tolerance and Hirth-type serration on its lower face, and a plurality of centering members which are rigidly affixed to the machine frame around the turning axis of the switch plate at equal angular intervals and have Hirth-type serration on their top face which mate axially with the serration of the workpiece receivers after every turn of the switch plate and which can be brought into and out of engagement by an axial movement of the switch plate.
 2. A switch plate machine according to claim 1 wherein the switch plate is elastically resilient in the axial direction near the periphery thereof.
 3. A switch plate machine according to claim 2 wherein the radially outer zone of the switch plate is divided by radial slots into elastic segments each of which carries one workpiece receiver. 